Home > Conference materials > Papers > Thermodynamic Possibilities and Constraints for Pure Hydroden Production by Iron Based Chemical Looping Process at Lower Temperatures
Original title:
Thermodynamic Possibilities and Constraints for Pure Hydroden Production by Iron Based Chemical Looping Process at Lower Temperatures
Translated title:
Termodynamické možnosti a omezení pro výrobu čistého vodíku pomocí železa s využitím cyklického chemického procesu za nižších teplot
Authors:
Svoboda, Karel ; Slowinski, G. ; Rogut, J. ; Siewiorek, A. Document type: Papers Conference/Event: International Congress of Chemical and Process Engineering CHISA 2006 /17./, Praha (CZ), 2006-08-27 / 2006-08-31
Year:
2006
Language:
eng Abstract:
[eng][cze] Iron offers possibility of transformation of a reducing gas ( CO, syngas, methane etc.) into hydrogen by a cyclic process based on iron oxide reduction and release of hydrogen in the next step by steam oxidation. Thermodynamics and chemical equilibrium for reduction of magnetite by hydrogen, carbon monoxide, model syngas and methane and for oxidation of iron by steam has been studied in a temperature range 400 – 850 K. Attention was concentrated also on possible formation of undesired soot, iron carbide and iron carbonate as precursors for CO and CO2 formation in the steam oxidation step. Oxidation of iron by steam is thermodynamically favoured at temperatures 400 – 800 K enabling high hydrogen yields. Iron oxide (magnetite) reduction is the more difficult step, requiring rather higher temperature and higher CO, H2 or methane concentrations in gaseous mixtures.V rozmezí teplot 400 – 1000 K byly studovány termodynamika a chemické rovnováhy pro redukci Cr2O3 , Mn3O4 a NiO vodíkem , CO, syntetickým plynem, metanem a pro oxidaci relevantních produktů Cr, MnO a Ni vodní parou. Pozornost byla soustředěna také na možnou tvorbu nežádoucích sazí, karbidů a uhličitanů během redukčního kroku, které vedouc následně k uvolňování CO a CO2 v oxidačním kroku. Redukce Cr2O3 a MnO na kovový chrom a mangan pomocí vodíku, CO nebo metanu je vyloučena za teplot 400 – 1000 K. Redukce Mn3O4 a NiO vodíkem, CO a CH4 za těchto nižších teplot je termodynamicky preferována.
Keywords:
hydrogen; iron; thermodynamics Project no.: CEZ:AV0Z40720504 (CEP) Host item entry: Summaries 4., ISBN 80-86059-45-6
Institution: Institute of Chemical Process Fundamentals AS ČR
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Document availability information: Fulltext is available at the institute of the Academy of Sciences. Original record: http://hdl.handle.net/11104/0143055